Hydraulically operated connector crimping tool



United States Patent 2,941,430 HYDRAULICALLY OPERATED CONNECTOR CRIMPINGTOOL Martin L. Klingler, Hershey, Pa., assignor to AMP Incorporated,Harrisburg, Pa. Filed Nov. 19, 1957, Ser. No. 697,480 1 Claim. (Cl.81-15) This invention relates to tools for crimping electricalconnectors onto conductors. Particularly it concerns tools of the typeoperated by fluid pressure.

Fluid operated crimping tools are generally heavy, bulky, and diflicultto hold while making the crimped connection. The present inventionprovides a fluid operated crimping tool that is light, compact andeasily held while making the crimp. In spite of its compactness, thetool of the instant invention incorporates a dual set of pistons, onehaving a long stroke and the other having a short stroke. The pistonsare so arranged that the length of the short stroke increases the lengthof the long stroke.

Other objects and attainments of the present invention will becomeapparent to those skilled in the art upon reading of the followingdetailed description when taken in conjunction with the drawings inwhich there is shown and described an illustrative embodiment of theinvention; it is to be understood, however, that this embodiment is notintended to be exhaustive nor limiting of the invention but is given forpurposes of illustration in order that others skilled in the art mayfully understand the invention and the principles thereof and the mannerof applying it in practical use so that they may modify it in variousforms, each as may be best suited to the conditions of a particular use.

Figure 1 is a plan view of a tool incorporating the principles of thisinvention, as shown in open or inoperative position;

Figure 2 is a view similar to Figure 1 showing the tool in closed oroperative position.

A device illustrating one form of the invention, as shown in Figure 1,includes a body member 10, which constitutes a fluid cylinder. Platemembers 12 and 14 close opposite ends of the cylinder. A piston 16 isslidably mounted centrally of the cylinder for axial travel therein.Piston rod 18 is secured to the piston 16 and is guided in an aperture20 in plate 12. An aperture 22 in the plate 14 permits entrance of fluidinto the cylinder 10, against the working face of the piston 16. Thedevice shown in Figure l includes a spring 24 which bears against thenon-working face of the piston, to return the piston to the inoperativeposition shown in Figure l.

A valve structure, generally designated V," located at one end of thecylinder, controls the flow of fluid through the aperture 22. Thevalving means will be disclosed in greater detail further on in thespecification.

The plate member 12 closing the other end of the cylinder has projectingwalls which form a second cylinder 26 of smaller diameter than the firstcylinder 10. The projecting ends of the walls are fitted with a hollowcap 28 having a yoke 30 at one end thereof.

A second piston 32 is hollow and has a hollow piston rod 34 extendingfrom it. The piston and piston rod are axially movable and a spring 36yieldingly retains the piston in the inoperative position shown inFigure 1. The hollow chamber 38 is filled with fluid and suitablesealing rings are provided.

A pair of cooperating dies 40, 40' is secured to the hollow piston rod34 and the yoke 30, respectively, so that relative movement of thesemembers brings the dies into crimping relationship.

The valving structure includes a valve casing 50 with an inlet-outletport 52 secured to a fluid supply (not Patented June 21, 1960 shown). Aspring operated needle valve 54 within the casing is actuated toward oraway from a valve seat 55 by a slidable operating member 56. The member56 is operated by cam 58, carried by handle 60. The spring 62 returnsthe needle valve, actuating member and handle to inoperative position.

During the operational cycle, movement of the handle in a clockwisedirection (Figure 2) causes the cam 58 to urge the member 56 against thevalve 54. The valve 54 is moved away from the valve seat 55 to permitcompressed air into the system. Release of the handle (Figure 1) permitsthe needle valve to return to its closed position against the valve seat55 under the action of spring 62. Exhaust air is bled through thesliding member 56 and escapes to the atmosphere through a port 64 in thesliding member. It is noted that the abutment of the end of the needlevalve and the sliding member closes the exhaust path during theoperating cycle.

Operation The tool is initially in the position shown in Figure 1. Aconnector is inserted between the dies and a conductor threaded into theconnector. Actuation of the handle 60 causes operating member 56 todisplace needle valve 54, admitting fluid pressure into the chamber 10,against the working face of the piston 16. The piston 16 is drivenupwardly against the spring 24. Upward travel of the piston rod 18causes it to enter the upper chamber 38 and displace the fluid therein.The displaced fluid operates against the working face of piston 32,driving it upwardly to close the dies 40, 40. This effects the crimpedconnection. Release of the handle 60 permits fluid to bleed out of thechamber 10 and springs 24 and 36 return their respective pistons to theinitial position. This opens the dies and permits the crimped connectionto be withdrawn.

Changes in construction will occur to those skilled in the art andvarious apparently different modifications and embodiments may be madewithout departing from the scope of the invention. The matter set forthin the foregoing description and accompanying drawings is offered by wayof illustration only. The actual scope of the invention is intended tobe defined in the following claims when viewed in their properperspective against the prior art.

I claim:

A tool for crimping electrical connectors including, a cylinder formingassembly having a fixed die at one end, a hollow piston slidable in thecylinder and carrying a die on one end which protrudes from thecylinder, whereby the dies are in cooperative relationship, an openingin the other end of the piston in fluid communication with the cylinder,means norm-ally urging the piston away from the fixed die, a body ofliquid in the hollow piston adapted to flow into the cylinder, a chambercoaxial with the first cylinder, a wall separating the chamber and thecylinder, an aperture in said wall, a second piston slidable in thechamber, means urging the second piston away from the wall, a piston rodextending from one side of the second piston through the aperture in thewall, means for directing fluid pressure against the working face of thesecond piston to urge it toward the wall, and means for venting thefluid pressure at the completion of the stroke, whereby the piston rodenters the hollow piston and replaces the fluid therein to cause thefluid to drive the piston toward the fixed die.

References Cited in the file of this patent UNITED STATES PATENTS1,007,349 Gerdau Oct. 31, 1911 2,396,359 Smith et al. Mar. 12, 19462,696,850 Peterson Dec. 14, 1954

